JP2018051836A - Pressure sensitive sheet for inkjet recording and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensitive sheet for inkjet recording excellent in color optical density of printing even when printed by an inkjet type printer using an aqueous pigment ink, excellent in ink fixability and having no transfer of printed contents to an opposing surface.SOLUTION: There is provided a pressure sensitive sheet for inkjet recording having a pressure sensitive adhesive coating layer containing a non-detachable pressure sensitive adhesive base agent, a fine particle filler, a binder and a water soluble polyvalent metal salt on at least one surface of the base paper, and containing intermediate saponification type polyvinyl alcohol with saponification degree of 90 to 98 mol% as the binder.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a pressure-sensitive adhesive sheet for ink-jet recording suitable for printing by an ink-jet printer, and more particularly to a pressure-sensitive adhesive sheet for ink-jet recording suitable for printing by an ink-jet printer using a pigment-type aqueous ink.

  After printing confidential information and advertisement information on the surface coated with pressure-sensitive adhesive, fold the paper so that the pressure-sensitive adhesive coated surface becomes the inner surface, and press and seal by applying predetermined pressure Paper is used for various purposes. For the purpose of reducing postage costs, such pressure-bonded papers are detachably pressure-bonded with the personal information printed side facing inward, and used as postcards (hereinafter abbreviated as pressure-bonded postcards) instead of sealed letters. It is also used in various fields as pressure-bonded printed materials such as pressure-bonded advertisements.

  An example of the manufacturing method of the pressure-bonded paper is as follows. First, a pressure-sensitive adhesive composition that can be bonded by applying a certain pressure and can be re-peeled is applied to the surface of the base paper. Print on a form printer with the ink. Next, personal information (confidential information), which is variable information, is printed by various printers, folded into two or three folds, etc., and then passed between the pressure rolls of the dry sealer to apply the pressure sensitive adhesive composition. By bonding the finished surfaces together, a form is provided to the user. Here, if the paper is cut to postcard size, it becomes a crimped postcard. After receiving the pressure-bonded paper or pressure-bonded postcard, the recipient peels off the coated surface of the pressure-sensitive adhesive that has been bonded and reads the confidential information printed inside.

  In the manufacturing process of pressure-bonded paper, the pressure-sensitive paper is stored in a state where fixed information (common information) is printed on the pressure-bonded paper in advance, and confidential information is printed by using the stored pressure-sensitive paper as much as necessary. It is common to be provided to. For this reason, there is often a certain amount of days after the fixed information is printed and before the confidential information is printed and provided to the customer, and the ink used for printing the fixed information is required to have weather resistance. UV curable ink is generally used.

  An ink jet printer performs recording by ejecting ink as innumerable droplets by various means and adhering it to a recording sheet. However, in recent years, technical progress has been remarkably increased. It became possible and colorization became easy. As a result, it has become possible to obtain images that are not inferior to those of multi-color offset printing and color electrophotographic systems. In addition, inkjet printers have a running cost in color printing that is electrophotographic. Compared to other printers, it is cheaper and has become widespread. For these reasons, in recent years, inkjet printers are often used for printing confidential information on pressure-sensitive paper.

  Inkjet recording paper has been used for posters and drafting applications. For this reason, ink-jet recording paper and ink-jet recording ink are required to have more color, color reproducibility and image weather resistance than ever before. It is supposed to be. In response to these demands, ink jet recording inks and base materials (ink jet recording paper) have been improved. Recently, in addition to the conventionally known water-based dye inks, water-based pigment inks in which colorant pigments are dispersed in water are also used. As a result, the above requirements are met.

  Among these aptitudes, the improvement of the weather resistance due to the use of water-based pigment ink has made it possible to print fixed information with an ink jet printer instead of form printing with UV curable ink. For this reason, since the form printing process can be reduced by simultaneously printing fixed information and confidential information with an ink jet printer, it is expected to lead to a large cost improvement.

  On the other hand, when water-based pigment ink is used for the pressure-sensitive recording paper for ink jet recording, there are still some problems, and it is necessary to give new aptitude to the pressure-sensitive paper in order to cope with these problems. Specifically, it is as follows.

(1) High color density Since the colorant pigment in the aqueous pigment ink is insoluble in water unlike the colorant dye, the ratio of the colorant pigment may be increased too much in order to stably disperse the colorant pigment in the ink. It is not possible to obtain a clear color. In addition, one method of increasing the color density is to increase the blending ratio of a filler such as silica having high ink absorbency. However, in order to maintain an appropriate adhesive force as a pressure-bonded postcard, In this case, it is not preferable to increase the blending amount of the filler in the pressure-sensitive adhesive coating layer) to that of a general ink jet recording paper.

(2) Improvement of ink fixability (prevention of print transfer when opened)
The colorant pigment in the aqueous pigment ink is less absorbable into the coating layer of the pressure-sensitive adhesive composition than the colorant dye, and the colorant pigment tends to remain on the coating layer. For this reason, the color material pigment remaining on the coating layer is transferred to the opposite surface while being pressed and held with a dry sealer, and the characters and barcodes are interpreted by the transferred color material pigment when the pressure-bonded postcard is peeled off. There is a problem that becomes difficult.

(3) Improvement of surface strength (preventing dirt on the pressure roll of dry sealer)
If the blending ratio of a highly water-absorbing filler, such as silica, is increased in order to absorb water-based pigment ink having poor absorbability, the coating layer strength of the printed coating layer will be weakened when the ink adhesion amount is increased. In addition, when pressure-bonding paper is pressure-bonded with a dry sealer and sealed, the colorant pigment is peeled off from the pressure roll of the dry sealer to contaminate the roll, and if this state continues, it accumulates in the pressure roll. There arises a problem that the stains contaminate the crimped paper.

  In order to solve these problems, various proposals related to pressure-sensitive paper for ink jet recording have been made. For example, in Patent Document 1, colloidal fine particles of 5 to 25 such as silica and calcium carbonate having an average particle diameter of 1 to 100 nm with respect to 100 parts by mass of a styrene-methyl methacrylate graft copolymer natural rubber adhesive base (solid content). An information-carrying sheet excellent in fixability and water resistance of inkjet ink has been proposed by using a pressure-sensitive adhesive composition containing a mass part (see Patent Document 1).

  Further, it contains amorphous silica having an apparent specific gravity measured in accordance with JIS K 6220 of 0.25 g / ml or more as the fine particle filler of the adhesive layer, and the amorphous silica content in the adhesive layer is By setting the content to 20 to 50% by mass, a pressure-sensitive adhesive sheet excellent in suitability for high-speed inkjet printers has been proposed (see Patent Document 2).

  Further, the pseudo-adhesive layer contains a non-peelable adhesive mainly composed of natural rubber, a completely saponified polyvinyl alcohol, and a fine particle filler. These fine particle fillers are precipitated synthetic silica and gel synthetic silica. By adjusting the blending mass ratio of 9: 1 to 7: 3, while satisfying the adhesive / peeling characteristics, the offset printing suitability, the recording density in the ink jet recording, the bleeding of the printing (feathering), the drying of the ink There has been proposed a pseudo-adhesive paper having improved absorbability, water resistance of ink, and transferability of a printed part during pressure bonding (see Patent Document 3).

  In addition, even if the pseudo-adhesive layer is a pseudo-adhesive sheet for pigment ink printing containing a fine particle filler together with an adhesive, and the precipitation method silica is used as the fine particle filler, the pigment ink is used for printing. There has been proposed a pseudo-adhesive sheet for pigment ink printing that is free from the risk of rubbing dirt and the like, and that does not cause the surface strength of the pseudo-adhesive layer provided on the surface of the substrate sheet to be weakened (see Patent Document 4). ).

JP 2001-262105 A JP 2004-084466 A JP 2009-249745 A JP 2013-212671 A

  However, the methods described in Patent Documents 1 and 2 do not provide sufficient surface strength and ink fixing effect when applied to a high-speed inkjet printer using aqueous pigment ink. For this reason, it has not reached the point of imparting ink smear prevention, non-transferability and the like in the dry sealer.

  In addition, the methods described in Patent Documents 3 and 4 did not provide sufficient high color density of an image when applied to a high-speed inkjet printer using aqueous pigment ink. .

  The present invention has been made in order to solve the above-described problems. Even when printing is performed with an ink jet printer using an aqueous pigment ink, the color density of printing is excellent, and the ink fixing property is excellent. An object of the present invention is to provide a pressure-sensitive recording paper for ink-jet recording in which printed contents are not transferred to the opposite surface.

  Another object of the present invention is that the pressure-sensitive adhesive coating layer is excellent in surface strength and does not stain the pressure roll of the dry sealer when sealing the postcard with the dry sealer. , To provide a pressure-sensitive adhesive sheet for inkjet recording

  Furthermore, other objects and effects of the present invention will be easily understood by those skilled in the art by referring to the following description.

  In order to solve the above-mentioned problems, a pressure-sensitive adhesive paper for ink-jet recording according to the present invention comprises a non-peelable pressure-sensitive adhesive base, a fine particle filler, a binder, and a water-soluble polyvalent metal salt on at least one surface of the base paper. A pressure-sensitive adhesive coating layer containing an intermediate saponification type polyvinyl alcohol having a saponification degree of 90 to 98 mol% as the binder, and using an aqueous pigment ink Used for an ink jet printer.

  According to such a configuration, the color density of the pressure-sensitive adhesive coating layer surface (hereinafter abbreviated as “color developability”) is high, and it is applied to the opposite surface of the print recorded on the confidential surface at the time of peeling after pressure bonding with a dry sealer. Transfer (hereinafter abbreviated as “print transfer to the opposite surface”) is suppressed, and adhesion of the printed pressure-sensitive adhesive coating layer to the pressure roll of the dry sealer (hereinafter, referred to as “printing transfer to the opposite surface”) (Abbreviated as “stain of pressure roll”). In particular, by adding an intermediate saponification type polyvinyl alcohol having a saponification degree of 90 to 98 mol%, printing transfer to the opposite surface is remarkably suppressed.

  In the pressure-sensitive adhesive paper for ink-jet recording of the present invention, it is sufficient that the pressure-sensitive adhesive coating layer provided on at least one surface satisfies the above conditions, and the other surface is pressure-sensitive adhesive having the same configuration. What is necessary is just to employ | adopt suitably structures, such as not providing an agent coating layer, a pressure sensitive adhesive coating layer of a different structure, and a pressure sensitive adhesive coating layer.

  In a preferred embodiment of the present invention, the binder may be an intermediate saponified polyvinyl alcohol having a saponification degree of 92 to 96 mol%.

  According to such a configuration, since the degree of saponification of polyvinyl alcohol is more limited, it is possible to further suppress printing transfer to the facing surface.

  In a preferred embodiment of the present invention, the water-soluble polyvalent metal salt may be magnesium sulfate and / or calcium chloride.

  According to such a configuration, the ink fixing property is excellent, and the printing transfer to the opposite surface can be further suppressed.

  In preferable embodiment of this invention, the range of 95-170 mass parts with respect to 100 mass parts of said fine particle fillers may be sufficient as the compounding quantity of the said non-peeling pressure-sensitive adhesive.

  According to such a configuration, since the blending amount of the non-peelable pressure-sensitive adhesive base is in an appropriate range, transfer to the opposite surface is less likely to occur, and the ink absorbability, fixability, and color developability are also improved. improves.

  In a preferred embodiment of the present invention, the fine particle filler may contain amorphous silica.

  According to such a configuration, since the amorphous silica is porous and has a high absorbability with respect to the aqueous pigment ink, it is possible to obtain a pressure-sensitive adhesive paper for ink jet recording that is more excellent in ink absorbability and ink fixability.

  In a preferred embodiment of the present invention, the fine particle filler may contain gel silica.

  According to such a configuration, the pressure of ink jet recording is less likely to stain a blanket or a plate even when a ruled line or general information is printed by form printing with UV curable ink or the like by improving the strength of the coating layer. Can be paper.

  In a preferred embodiment of the present invention, the amount of oil absorption measured based on ISO 787-5 of the amorphous silica may be in a range of 180 to 400 ml / 100 g.

  According to such a configuration, it is possible to obtain a pressure-sensitive adhesive sheet for ink jet recording that is more excellent in color development of an image and has good ink absorbability and ink fixability.

  In preferable embodiment of this invention, the range of 1.0-15.0 micrometers may be sufficient as the average particle diameter by the laser diffraction method of the said amorphous silica.

  According to such a structure, it is excellent in the adhesive strength of the coating layer surface, and coating layer strength, and the press roll stain | pollution | contamination of a dry sealer and the printing transfer to an opposing surface are suppressed more.

  In a preferred embodiment of the present invention, as the fine particle filler, a wheat starch having an average particle diameter of 10 to 20 μm by laser diffraction method is further added in a solid content of 10 to 10 with respect to the fine particle filler excluding the wheat flour starch. You may contain in 30 mass%.

  According to such a configuration, by further using the wheat starch of the above average particle diameter, the adhesive strength is properly adjusted, the printing transfer to the opposite surface is further suppressed, and the occurrence of blocking is also suppressed. .

In a preferred embodiment of the present invention, the rice basis weight may be 60 to 200 g / m ² . According to such a structure, it can be set as the inkjet recording pressure-sensitive paper suitable for use as a postcard paper.

  The present invention can also be understood as a method for manufacturing a pressure-sensitive adhesive paper for ink jet recording.

  A method for producing a pressure-sensitive adhesive paper for ink-jet recording according to the present invention comprises a step of preparing a base paper, a non-peelable pressure-sensitive adhesive base, a fine particle filler, a binder, and a water-soluble polyvalent metal salt. A step of adjusting a pressure-sensitive adhesive composition using a composition raw material, and a step of applying the pressure-sensitive adhesive composition to at least one surface of the base paper to provide a pressure-sensitive adhesive coating layer The gel filler is included as the fine particle filler, and the binder contains intermediate saponified polyvinyl alcohol having a saponification degree of 90 to 98 mol%.

  According to such a configuration, it is possible to easily manufacture a pressure-sensitive adhesive sheet for inkjet recording that has a high color density of printing, suppresses printing transfer to the opposite surface, and does not stain the pressure roll of the dry sealer.

  The pressure-sensitive adhesive paper for ink-jet recording according to the present invention has a high color density, and the pressure-sensitive adhesive coating layer has a sufficient surface strength, so that even when an aqueous pigment ink is used, the transfer of printing to the opposite surface is suppressed. The pressure roll is not soiled when it is pressure-bonded with a dry sealer.

  Moreover, the surface strength of the pressure-sensitive adhesive composition coating layer is sufficiently high by selecting an optimum fine particle filler to be added to the pressure-sensitive adhesive composition. High surface strength enables fine line images to be printed appropriately. Even when water-based pigment ink is used, high ink fixability is obtained, color developability is good, and printing transfer to the opposite surface Further, contamination of the pressure roll and the like are further suppressed.

It is a graph (the 1) which shows the mixing | blending of the crimping | compression-bonding paper for IJ recording in an Example. It is a graph (the 2) which shows the mixing | blending of the crimping | compression-bonding paper for IJ recording in an Example. It is a graph which shows the mixing | blending of the crimping | compression-bonding paper for IJ recording in a comparative example. It is a table | surface which shows the mixing | blending and physical-property evaluation result of the crimping | compression-bonding paper for IJ recording obtained by the Example and the comparative example.

  Hereinafter, preferred embodiments of the present invention will be described in detail, but the present invention is not limited to the following descriptions.

  As described above, in the printing by the ink jet printer on the pressure-sensitive recording paper for ink jet recording, the ink jet ink ejected from the ink nozzle first adheres to the surface of the paper as a droplet, and then the dye / The pigment penetrates into the paper and fixes. Here, when water-based pigment ink is used, since the color material pigment in the water-based pigment ink has poor absorbability to the pressure-sensitive adhesive coating layer, only water in the ink penetrates into the paper, and the color material pigment Tends to remain on the surface of the pressure-sensitive adhesive coating layer. If the colorant pigment remaining on the surface of the pressure-sensitive adhesive coating layer is insufficiently absorbed or fixed, a problem of printing transfer to the opposite surface occurs. In addition, when the ink adhesion amount is increased in order to improve the color developability with the aqueous pigment ink, there is a possibility that the problem of contamination of the pressure roll may occur because the ink is not sufficiently absorbed by the coating layer.

  In order to solve these problems, the pressure-sensitive recording paper for ink jet recording according to the present invention employs the following configuration.

  The pressure-sensitive adhesive sheet for ink jet recording according to the present invention comprises a pressure-sensitive adhesive coating layer comprising a pressure-sensitive adhesive composition on at least one surface of a base paper. In the present invention, various information papers such as kraft paper, foam paper, high quality paper, medium quality paper, OCR paper and the like can be used as appropriate as the base paper used for the pressure-sensitive recording paper for ink jet recording. These papers may be commercially available, but when manufactured from pulp, if necessary, a wet paper strength enhancer or the like may be added to impart water resistance. Here, the fiber material of the base paper is not particularly limited, and general wood pulp can be appropriately selected and used. However, in consideration of environmental aspects, waste paper generated in the process, waste paper pulp and kenaf, Non-wood raw materials such as bagasse and bamboo may be used.

In the present invention, the rice basis weight of the pressure-sensitive adhesive paper for ink-jet recording is not particularly limited, but is preferably in the range of 60 to 200 g / m ² in consideration of processing into a pressure-sensitive postcard paper. The selection of the tsubo is performed so as to satisfy the weight standard of the postcard in the postal method, and the weight is set to be in the range of 2 to 6 g when the postcard is formed into a crimped postcard.

  In the present invention, the “pressure-sensitive adhesive composition” refers to a composition that can be bonded by pressing without being bonded in a normal state and can be peeled off by manual peeling after pressing. Non-releasable adhesive base responsible for the effect, fine particle filler that contributes to adjustment of adhesive strength and ink absorption, binder that contributes to surface strength of the pressure-sensitive adhesive coating layer, and ink fixability The main material is a water-soluble polyvalent metal salt to be imparted.

  In the present invention, examples of the non-releasable pressure-sensitive adhesive base that can be used in the pressure-sensitive adhesive composition include natural rubber latex and synthetic rubber latex. As natural rubber latex, natural rubber latex obtained by graft polymerization of natural rubber with methyl methacrylate and styrene, natural rubber latex mixed with natural rubber and methyl methacrylate, natural rubber latex and protection A mixture with a colloidal acrylic copolymer emulsion or the like can be suitably used because it easily develops an appropriate adhesion ability. Examples of synthetic rubber latex include styrene-butadiene latex and acrylonitrile latex. These latexes can be used alone or in combination of two or more.

  In the present invention, the blending amount of the non-peelable pressure-sensitive adhesive base is preferably in the range of 95 to 170 parts by mass with respect to 100 parts by mass of the fine particle filler in terms of solid content. When the blending amount of the non-peeling pressure-sensitive adhesive base is less than 95 parts by mass, the blending amount of the non-peeling pressure-sensitive adhesive base is small, so that sufficient adhesive force cannot be obtained, and it is sealed by pressure bonding. A strong pressure is required when processing. Since the pressure-bonding postcard paper is sealed with a strong pressure, a strong pressure is also applied between the opposed surfaces that have been pressure-bonded. On the other hand, when the blending amount of the non-peelable pressure-sensitive adhesive base exceeds 170 parts by mass, the blending ratio of the fine particle filler is relatively lowered, so that the ink absorbability and the fixing property are lowered, and the pressure-sensitive adhesive. Since the agent coating layer cannot fix the ink-jet ink sufficiently and quickly, the color developability may be deteriorated.

  In the present invention, the fine particle filler to be blended in the pressure-sensitive adhesive composition is not particularly limited, and a known fine particle filler such as kaolin, calcined kaolin, talc, calcium carbonate, amorphous silica or the like is used. be able to. Among these, it is preferable to use amorphous silica because of its excellent ink absorbability.

  Since amorphous silica is porous and has a high absorption capacity for water-based pigment inks, the ink absorbability and ink of the pressure-sensitive adhesive coating layer when blended in a pressure-sensitive adhesive composition Fixability is improved, and the aqueous pigment ink can be quickly absorbed and fixed. Here, the degree of ink absorption of amorphous silica can be evaluated by the amount of oil absorption, and it is generally considered that as the amount of oil absorption increases, the absorptivity of the inkjet ink increases.

  The amorphous silica used in the present invention preferably has an oil absorption (measured simply as “oil absorption” hereinafter) of 180 to 400 ml / 100 g measured based on ISO 787-5. More preferably, it is 220-355 ml / 100g. By using such amorphous silica, it is possible to obtain a pressure-sensitive adhesive paper for ink jet recording that has excellent color developability of printing / printed images, good ink absorbability and ink fixability, and no print transition at the time of opening. .

  When the oil absorption of amorphous silica is less than 180 ml / 100 g, the ink absorbability becomes too weak and the color developability deteriorates, and sufficient fixing ability of the aqueous pigment ink is imparted to the pressure-sensitive adhesive coating layer. In some cases, printing transfer to the opposite surface may occur. Further, when the oil absorption amount of the amorphous silica exceeds 400 ml / 100 g, in addition to the ink absorbability becoming excessively strong, even the adhesive is absorbed due to the excessive absorbency, and the pressure roll is soiled. There is a fear.

  The average particle diameter of the fine particle filler by the laser diffraction method is preferably 1.0 to 15.0 μm when amorphous silica is used as the fine particle filler. More preferably, it is 2.0-12.5 micrometers. By using such a fine particle filler having an average particle diameter, the adhesive strength and the coating layer strength are preferable, and the pressure roll stain of the dry sealer and the printing transfer to the opposite surface are further suppressed, and recording by an ink jet printer is performed. The color developability of the image can be further improved.

  If the average particle size of the fine particle filler is less than 1.0 μm, the surface strength may be lowered and printing transfer to the opposing surface may occur. On the other hand, if the average particle diameter of the fine particle filler exceeds 15.0 μm, smoothness is lost due to the particle diameter of the fine particle filler itself on the surface of the coating layer, and there is a possibility that printing transfer to the opposing surface occurs.

  In the present invention, it is preferable to use gel silica among amorphous silica as the fine particle filler. Amorphous silica includes gel method silica and precipitation method silica depending on the production method, but gel method silica tends to improve the coating layer strength as compared with precipitation method silica. Therefore, by including gel method silica as a fine particle filler, when printing ruled lines and general information by form printing with UV curable ink, etc., it should be a pressure-sensitive adhesive paper for inkjet recording that does not easily stain blankets and plates. Can do.

  Further, as the fine particle filler of the present invention, wheat starch having an average particle diameter of 10 to 20 μm by laser diffraction method is blended in a solid content range of 10 to 30% by mass with respect to the fine particle filler excluding wheat starch. May be. By blending wheat starch in an appropriate range, the adhesive strength is properly adjusted to improve printing transfer to the opposite surface, which is larger than the case of using only amorphous silica on the pressure-sensitive adhesive coating layer surface. Concavities and convexities are generated to improve the absorbability of the aqueous pigment ink and improve blocking.

  As described above, in the present invention, a binder is blended in order to improve the strength of the pressure-sensitive adhesive coating layer. Here, an intermediate saponified polyvinyl alcohol having a saponification degree of 90 to 98 mol%, more preferably 92 to 96 mol% is used as the binder. Although the reason is not clear, the strength of the pressure-sensitive adhesive coating layer is improved by using an intermediate saponified polyvinyl alcohol having a saponification degree of 90 to 98 mol% in combination with a water-soluble polyvalent metal salt as a binder. At the same time, it is possible to suppress printing transfer to the facing surface. Here, when the degree of saponification of the intermediate saponified polyvinyl alcohol exceeds 98 mol%, the coating property of the polyvinyl alcohol is excessively increased, or the ink absorption is hindered and the ink remains on the surface of the coating layer. The suppression of printing transfer to the surface cannot be satisfied. On the other hand, when the saponification degree is less than 90 mol%, the ink drying property is impaired and the surface strength is also lowered. Furthermore, the adhesive performance of the pressure-sensitive adhesive coating layer is lowered. If the adhesive performance is reduced, in order to give an appropriate adhesive strength as a pressure-bonded postcard, pressure bonding at a higher pressure is required. However, if pressure bonding at a higher pressure is performed, Printing transition is likely to occur.

  The binder content in the pressure-sensitive adhesive coating layer is preferably 24 to 48 mass% in terms of solid content with respect to the fine particle filler. More preferably, it is 28-40 mass%. When the content of the binder exceeds 48% by mass, the absorptivity of the aqueous pigment ink is impaired, and there is a possibility that the suppression of printing transfer to the opposite surface cannot be satisfied. On the other hand, when the content is less than 24% by mass, the pressure-sensitive adhesive coating layer is insufficient in strength, and there is a possibility that stains on the pressure roll cannot be suppressed.

  Further, as a binder, in the range not impairing the intended effect of the present invention, phosphate esterified starch, oxidized starch, hydroxyethyl starch, partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, acrylic resin, A polyvinyl acetate resin, an ethylene-vinyl acetate resin, or the like can be used in combination. Further, various modified polyvinyl alcohols such as silanol modification, carboxyl group modification, acetoacetyl group modification, and cation modification may be used.

  In the present invention, in addition to the main component of the pressure-sensitive adhesive composition, a water-soluble polyvalent metal salt is blended in the pressure-sensitive adhesive composition as an ink fixing agent. Examples of the water-soluble polyvalent metal salt include hydrochloric acid, nitric acid, and sulfate of calcium and magnesium. Among these, magnesium sulfate and / or calcium chloride are preferable, and magnesium sulfate is more preferable because it is excellent in ink fixability and can suppress printing transfer to the opposite surface. The amount of the water-soluble polyvalent metal salt varies depending on the type of the water-soluble polyvalent metal salt. It is preferable. More preferably, it is 0.8-19 mass%. Moreover, if it is calcium chloride, it is preferable to set it as the range of 0.1-20 mass%, More preferably, it is 3-15 mass%. By blending a water-soluble polyvalent metal salt, the ink coloring property is improved and the effect of preventing bleeding is obtained. This is because the water-soluble polyvalent metal salt fixes the colorant pigment in the aqueous pigment ink to the surface of the pressure-sensitive adhesive coating layer, and the ink solvent is absorbed into the coating layer together with the color development of the ink. This is because the ink property is improved and ink bleeding is suppressed. Furthermore, in order to make a co-paper for water-based dye / pigment inks, dimethylamine / epihalohydrin polycondensation, which is an oligomer or polymer of primary to tertiary amines or quaternary ammonium salts, as long as the effects of the present invention are not impaired. Products, acrylamide / diallylamine copolymers, polyvinylamine copolymers, dicyandiamide, dimethyl / diallyl / ammonium chloride and other cationic resins as main components may be used in combination.

  Here, if the blending amount of the water-soluble polyvalent metal salt is too small, the ink is not fixed because the ink coloring property is deteriorated, and if it is too large, the fixing with the ink becomes too good, and the ink aggregated on the surface of the coating layer. If it remains, there is a possibility that suppression of printing transfer to the opposite surface cannot be satisfied.

  In the pressure-sensitive adhesive composition of the present invention, other known additives used in the technical field may be appropriately used as necessary. Examples of such additives include antifoaming agents, thickeners, pH adjusters, lubricants, dispersants, wetting agents, dyes, anti-aging agents, preservatives, and the like. In addition, when using these additives, it is necessary to pay attention to the blending amount so as not to impair the object of the present invention.

In the pressure-sensitive adhesive paper for ink-jet recording of the present invention, the non-peelable pressure-sensitive adhesive composition is preferably applied in the range of 2.0 to 12.0 g / m ² in terms of solid content on one side of the base paper. When the coating amount is less than 2.0 g / m ² , the adhesive force after the pressure treatment with the dry sealer is insufficient, and the adhesive state may become unstable. On the other hand, when the coating amount exceeds 12.0 g / m ² , the strength of the non-releasable pressure-sensitive adhesive coating layer is insufficient, and there is a possibility that stains on the pressure roll cannot be suppressed. Moreover, the coating apparatus for forming the pressure-sensitive adhesive coating layer on the base paper is not particularly limited, and a known coating apparatus used in the general coated paper manufacturing field can be appropriately used. For example, a blade coater, an air knife coater, a roll coater, a reverse roll coater, a curtain coater, a bar coater, a gravure coater, a size press coater, a bill blade coater, or the like can be used.

  Examples of the pressure-sensitive recording paper for ink-jet recording according to the present invention will be specifically described below, but the present invention is not limited thereby. In addition, unless otherwise indicated, the part and% in each Example and a comparative example show a dry mass part and mass%. Further, the oil absorption amount of silica in each Example and Comparative Example represents the oil absorption amount measured based on ISO 787-5, and the average particle size of the fine particle filler in each Example and Comparative Example is determined by laser diffraction method. The measured value of the volume average particle diameter by means of.

<Example 1>
Preparation of pressure-sensitive adhesive composition: gel silica having an average particle size of 7.0 μm and an oil absorption of 300 to 330 ml / 100 g as a fine particle filler (trade name: Cyloid C-807 / WWWR Grace Japan) Product) 100 parts by mass and 2.8 parts by mass of an antifoaming agent were added and sufficiently dispersed in water, and then an intermediate saponified polyvinyl alcohol having a saponification degree of 95.5 to 97.5 mol% (commercial product) Name: JM-17 / manufactured by NIPPON BI POVAL Co., Ltd.) 39 parts by mass, 122 parts by mass of a natural rubber latex obtained by polymerizing methyl methacrylate on a natural rubber as a non-peelable pressure-sensitive adhesive base, and a higher fatty acid type After adding 0.9 parts by weight of the lubricant, 5.6 parts by weight of magnesium sulfate and 16.7 parts by weight of wheat flour starch having an average particle size of 18 μm are added as an ink fixing agent. A coating composition was prepared.
Manufacturing method for pressure-sensitive recording paper for ink jet recording: Apply the prepared paint on both sides of foam paper with a basis weight of 113 g / m ² using an air knife coater so that the coating amount on each side becomes 6.0 g / m ^{2 in} solid content The ink-jet recording paper was obtained.

<Example 2>
In Example 1, an average particle size of 7.0 μm and an oil absorption amount of 300 to 330 ml / 100 g of gel silica (trade name: Cyloid C-807 / manufactured by W Earl Grace Japan) with an average particle size of 10. A pressure-sensitive adhesive sheet for ink jet recording was obtained in the same manner as in Example 1 except that the gel method silica (trade name: manufactured by HP39 / PQ Corporation) having an oil absorption of 280 ml / 100 g at 3 μm was used.

<Example 3>
In Example 1, gel method silica (trade name: Thyroid C-807 / manufactured by W Earl Grace Japan) having an average particle size of 7.0 μm and an oil absorption of 300 to 330 ml / 100 g is used at an average particle size of 12 μm. A pressure-sensitive adhesive sheet for ink jet recording is obtained in the same manner as in Example 1 except that the gel method silica (trade name: Cyroid C-812 / manufactured by WRL Grace Japan) having an oil absorption of 300 to 330 ml / 100 g is used. It was.

<Example 4>
In Example 1, an average particle size of 7.0 μm and a gel method silica (trade name: Thyroid C-807 / manufactured by WRL Grace Japan) having an oil absorption of 300 to 330 ml / 100 g are used. A pressure-sensitive adhesive paper for ink jet recording was obtained in the same manner as in Example 1 except that the silica gel gel (trade name: 23D / PQ Corporation) having an oil absorption of 270 ml / 100 g was changed to 4 μm.

<Example 5>
In Example 1, an average particle size of 7.0 μm and a gel method silica (trade name: Cyloid C-807 / manufactured by W Earl Grace Japan) having an oil absorption of 300 to 330 ml / 100 g is used. Pressure-sensitive adhesive paper for ink-jet recording in the same manner as in Example 1 except that it is changed to gel silica (trade name: Cyloid C-803 / manufactured by W Earl Grace Japan) having an oil absorption of 300 to 330 ml / 100 g at 0 μm. Got.

<Example 6>
The same procedure as in Example 1 was conducted except that the blending amount of intermediate saponified polyvinyl alcohol (trade name: JM-17 / manufactured by Nippon Vinegar Poval) was changed from 39 parts by mass to 28 parts by mass. Thus, a pressure-sensitive adhesive paper for ink jet recording was obtained.

<Example 7>
The same procedure as in Example 1 was conducted except that the blending amount of intermediate saponified polyvinyl alcohol (trade name: JM-17 / manufactured by Nippon Vinegar Poval) was changed from 39 parts by mass to 33 parts by mass. Thus, a pressure-sensitive adhesive paper for ink jet recording was obtained.

<Example 8>
The same procedure as in Example 1 was conducted except that the blending amount of intermediate saponified polyvinyl alcohol (trade name: JM-17 / manufactured by Nippon Vinegar Poval) was changed from 39 parts by mass to 45 parts by mass. Thus, a pressure-sensitive adhesive paper for ink jet recording was obtained.

<Example 9>
In Example 1, except that the blending amount of magnesium sulfate was changed from 5.6 parts by mass to 1.1 parts by mass, a pressure-sensitive adhesive sheet for ink jet recording was obtained in the same manner as Example 1.

<Example 10>
In Example 1, a pressure-sensitive adhesive sheet for ink jet recording was obtained in the same manner as in Example 1 except that the blending amount of magnesium sulfate was changed from 5.6 parts by mass to 3.3 parts by mass.

<Example 11>
In Example 1, except that the blending amount of magnesium sulfate was changed from 5.6 parts by mass to 11.1 parts by mass, a pressure-sensitive adhesive paper for ink jet recording was obtained in the same manner as Example 1.

<Example 12>
In Example 1, a pressure-sensitive adhesive sheet for ink jet recording was obtained in the same manner as in Example 1 except that the blending amount of magnesium sulfate was changed from 5.6 parts by mass to 16.7 parts by mass.

<Example 13>
In Example 1, except that magnesium sulfate was changed to calcium chloride, a pressure-sensitive adhesive paper for ink jet recording was obtained in the same manner as Example 1.

<Example 14>
In Example 1, an intermediate saponification type polyvinyl alcohol (trade name: JM-17 / manufactured by Nippon Acetate / Poval) was used as an intermediate saponification type polyvinyl alcohol (trade name) with a saponification degree of 92.5-94.5 mol%. : JT-13Y / manufactured by Nippon Vinegar Poval Co.) In the same manner as in Example 1, a pressure-sensitive adhesive paper for ink jet recording was obtained.

<Example 15>
In Example 1, an intermediate saponification type polyvinyl alcohol (trade name: JM-17 / manufactured by Nihon Acetate / Poval) is used as an intermediate saponification type polyvinyl alcohol (trade name) having a saponification degree of 96.0 to 98.0 mol%. : JM-23 / manufactured by Nippon Vinegar Poval Co.) In the same manner as in Example 1, a pressure-sensitive adhesive paper for ink jet recording was obtained.

<Example 16>
In Example 1, an intermediate saponification type polyvinyl alcohol (trade name: JM-17 / manufactured by Nippon Acetate / Poval) was used as an intermediate saponification type polyvinyl alcohol (trade name) with a saponification degree of 93.5 to 95.5 mol%. : JM-33 / manufactured by Nippon Vinegar Poval Co.) In the same manner as in Example 1, a pressure-sensitive adhesive paper for ink jet recording was obtained.

<Example 17>
In Example 1, gel method silica (trade name: Thyroid C-807 / manufactured by WRL Grace Japan) having an average particle size of 7.0 μm and an oil absorption of 300 to 330 ml / 100 g is used. A pressure-sensitive adhesive sheet for ink jet recording was obtained in the same manner as in Example 1 except that it was changed to precipitated silica (trade name: Carplex FPS-1 / Evonik) manufactured by 3 μm and having an oil absorption of 255 ml / 100 g.

<Example 18>
In Example 1, gel method silica (trade name: Cyloid C-807 / manufactured by W Earl Grace Japan) having an average particle size of 7.0 μm and an oil absorption of 300 to 330 ml / 100 g is used. A pressure-sensitive adhesive sheet for ink jet recording was obtained in the same manner as in Example 1 except that it was changed to precipitated silica (trade name: Carplex # 30 / manufactured by Evonik) having an oil absorption of 290 ml / 100 g at 0 μm.

<Comparative Example 1>
In Example 1, a partially saponified polyvinyl alcohol (trade name: JM-17 / manufactured by Nihon Acetate / Poval) was partially saponified polyvinyl alcohol (trade name) having a saponification degree of 87.0 to 89.0 mol%. : JP-18 / manufactured by Nihon Vinegar & Poval Co.) A pressure-sensitive adhesive paper for ink jet recording was obtained in the same manner as in Example 1.

<Comparative example 2>
In Example 1, intermediate saponification type polyvinyl alcohol (trade name: JM-17 / manufactured by Nippon Acetate / Poval) was completely saponified polyvinyl alcohol having a saponification degree of 99.3 mol% (trade name: V / A pressure-sensitive adhesive paper for ink jet recording was obtained in the same manner as in Example 1 except that it was changed to Nippon Vinegar Poval.

<Comparative Example 3>
In Example 1, a pressure-sensitive adhesive sheet for ink jet recording was obtained in the same manner as in Example 1 except that the blending amount of magnesium sulfate was changed from 5 parts by mass to 0 parts by mass.

<Comparative Example 4>
In Example 11, a pressure-sensitive adhesive sheet for ink jet recording was obtained in the same manner as in Example 11 except that the ink fixing agent magnesium sulfate was changed to DK6850 (polydimethylamine epichlorohydrin (PDMAE) / manufactured by Seiko PMC). It was.

<Comparative Example 5>
In Example 11, a pressure-sensitive adhesive sheet for ink-jet recording was obtained in the same manner as in Example 11 except that magnesium sulfate as the ink fixing agent was changed to Unisense CP-102 (polydiallyldimethylammonium chloride (pDADMAC), manufactured by Senca). It was.

<Comparative Example 6>
In Example 1, except that the intermediate saponified polyvinyl alcohol (trade name: JM-17 / Nippon Vinegar-Poval) was changed to Nipol LX430 (modified styrene-butadiene latex, manufactured by Nippon Zeon), In the same manner as in Example 1, a pressure-sensitive adhesive paper for ink jet recording was obtained.

[Preparation of samples for physical property evaluation]
CMYK solid-color printing with aqueous pigment ink was performed on the inkjet pressure-sensitive paper obtained in each Example and Comparative Example using an inkjet printer (Truepress Jet 520, manufactured by SCREEN). Thereafter, the pressure-bonded ink-jet paper after printing was prepared so as to have a moisture content of 5.5 to 7.0%, and 10 cm × 10 cm test pieces were cut and overlapped, and then dry sealer MS-9200II (stock) The confidential surfaces provided with the pressure-sensitive adhesive coating layer were pressure-bonded to each other by a company Duplo. When pressure bonding, the sealer gap was set so that the peel strength immediately after bonding was about 150 g / 25 mm width. The pressure-bonded surfaces of the pressure-bonded paper test pieces thus obtained were peeled off, and various evaluations were performed in the following manner.

[Evaluation of color development]
The color density of the recorded image on the pressure-bonded surface after peeling was visually evaluated. The highest color density was 6 and the lowest color density was 1, which was evaluated in 6 stages.

[Evaluation of transition to opposite surface]
After peeling, it was visually evaluated whether the recorded image printed on one pressure-bonding surface had transferred to the opposing surface (the other pressure-bonding surface). Evaluation was made on a 6-point scale, with 6 being the least transferred to the opposing surface and 1 being the most transferred to the opposing surface, and 3 or more were accepted.

[Evaluation of dirt on pressure roll]
The pressure-sensitive paper for inkjet recording was pressure-bonded to 10,000 postcards using a dry sealer MS-9200II, and then the degree of dirt on the pressure roll of the dry sealer was visually evaluated. The evaluation was made in 6 steps, with 6 being the least dirty of the pressure roll and 1 being the most dirty of the pressure roll.

[Surface strength]
Using a color developing device (Ishikawajima Sangyo: RI-II type) described in JIS K 5701, the presence or absence of white spots in the pressure-sensitive adhesive coating layer was visually determined. The coating layer with the smallest white spot was evaluated as 6 and the coating layer with the most white spot as 1 was evaluated in 6 stages.

[Evaluation of ink drying properties]
Using an ink jet printer (Truepress Jet 520, manufactured by SCREEN), CMYK solid color printing with aqueous pigment ink was continuously printed on an ink jet recording pressure-sensitive paper 6000 m at a printing speed of 128 m / min. Ink adhesion on the ink-jet recording pressure-sensitive paper after printing is visually observed, and is evaluated on a 6-point scale, with 6 being the least soiled paper and 1 being the most soiled paper. Passed. When the ink drying property is poor, the ink in the solid printing portion is transferred to a feed roll or the like of the ink jet printer, and the ink is further transferred to the paper, thereby causing ink stain on the ink jet recording pressure-sensitive paper.

  The composition of the pressure-sensitive adhesive composition paint in Examples and Comparative Examples is shown in FIGS. 1 to 3, and the evaluation of the properties of the pressure-sensitive adhesive paper for ink-jet recording obtained in Examples and Comparative Examples is shown in FIG. .

  As is apparent from the results of FIG. 4, the pressure-sensitive adhesive paper for ink jet recording obtained in Examples 1 to 18 is free from printing transfer to the opposite surface, ink drying property, surface strength, color development, and pressure roll stains. None of them had any problems in actual operation.

  On the other hand, the pressure-sensitive adhesive paper for ink-jet recording obtained in Comparative Example 1 was not practically usable in terms of ink drying property and surface strength. This is considered to be because the saponification degree of the polyvinyl alcohol used as the binder was less than 90 mol%.

  The pressure-sensitive adhesive paper for ink-jet recording obtained in Comparative Example 2 was not practically usable in terms of printing transfer to the opposite surface and ink drying properties. This is considered to be because the saponification degree of polyvinyl alcohol used as a binder exceeded 98 mol%.

  The pressure-sensitive adhesive paper for ink-jet recording obtained in Comparative Example 3 was not practically usable in terms of printing transfer to the opposite surface, surface strength, and color developability. This is probably because the water-soluble polyvalent metal salt was not blended.

  The pressure-sensitive adhesive paper for ink-jet recording obtained in Comparative Examples 4 and 5 was not practically usable in terms of printing transfer to the opposite surface, color development, and pressure roll contamination. This is considered to be caused by using an ink fixing agent other than the water-soluble polyvalent metal salt.

  The ink jet recording pressure-sensitive paper obtained in Comparative Example 6 was not practically usable in terms of printing transfer to the opposite surface, ink drying property, color development property, and pressure roll stain. This is considered to be because polyvinyl alcohol was not used.

Claims (11)

A pressure-sensitive adhesive paper for inkjet recording having a pressure-sensitive adhesive coating layer containing a non-peelable pressure-sensitive adhesive base, a fine particle filler, a binder, and a water-soluble polyvalent metal salt on at least one surface of the base paper. And
A pressure-sensitive adhesive paper for ink-jet recording, which contains an intermediate saponified polyvinyl alcohol having a saponification degree of 90 to 98 mol% as the binder and is used in an ink-jet printer using an aqueous pigment ink.   The pressure-sensitive adhesive paper for ink-jet recording according to claim 1, wherein the binder contains an intermediate saponified polyvinyl alcohol having a saponification degree of 92 to 96 mol%.   The pressure-sensitive adhesive sheet for ink jet recording according to claim 1 or 2, wherein the water-soluble polyvalent metal salt is magnesium sulfate and / or calcium chloride.   The amount of the non-releasable pressure-sensitive adhesive is in the range of 95 to 170 parts by mass with respect to 100 parts by mass of the fine particle filler, for inkjet recording according to any one of claims 1 to 3. Crimp paper.   The pressure-sensitive adhesive paper for ink-jet recording according to any one of claims 1 to 4, wherein the fine particle filler contains amorphous silica.   The pressure-sensitive adhesive paper for ink jet recording according to any one of claims 1 to 5, wherein the fine particle filler contains silica gel.   The pressure-sensitive adhesive sheet for ink-jet recording according to claim 5 or 6, wherein the amount of oil absorption measured based on ISO 787-5 of the amorphous silica is in a range of 180 to 400 ml / 100 g.   The pressure-sensitive adhesive paper for ink-jet recording according to any one of claims 5 to 7, wherein an average particle diameter of the amorphous silica by a laser diffraction method is in a range of 1.0 to 15.0 µm.   As the fine particle filler, further containing wheat starch having an average particle diameter of 10 to 20 μm by laser diffraction method in a range of 10 to 30% by mass in solid content with respect to the fine particle filler excluding the wheat flour starch. The pressure-sensitive adhesive paper for ink-jet recording according to any one of claims 5 to 8. The pressure-sensitive adhesive paper for ink-jet recording according to any one of claims 1 to 9, which has a basis weight of 60 to 200 g / m ² and is suitable as a postcard paper. Preparing a base paper;
Adjusting the pressure sensitive adhesive composition using a pressure sensitive adhesive composition raw material comprising a non-peelable pressure sensitive adhesive base, a particulate filler, a binder and a water-soluble polyvalent metal salt;
Coating at least one surface of the base paper with the pressure-sensitive adhesive composition to provide a pressure-sensitive adhesive coating layer,
Gel fine silica is included as the fine particle filler,
The method for producing a pressure-sensitive adhesive paper for ink-jet recording used in an ink-jet printer using an aqueous pigment ink, wherein the binder contains intermediate saponified polyvinyl alcohol having a saponification degree of 90 to 98 mol%.

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